Does risk of breast cancer increase without tamoxifen after chemo and surgery on one breast

Answer 1

I am not sure that the risk of getting cancer in one breast is significantly affected by chemo or by surgery in another breast -- at least am not aware of any studies to that effect. However, it is known that the fact of cancer in one breast is associated with 3-4 times higher risk of cancer in another breast (or in the remaining mammary tissue in the same breast).